Here is the full list of all 40 Goosebumps: The Game achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Complete the game without ever using the cell phone.
Grab every item you possibly can.
Gather all possible items dropped from the laundry chute.
Defeat Slappy while wearing the Haunted Mask.
Pry the Haunted Mask off your face.
Track down RL Stine in the phone book and give him a call.
Take pictures of every monster possible using the Haunted Camera.
Complete the game after draining your phone to 0% battery.
Have your life ended in 10 unique ways.
Finish the game in # turns or fewer.
Disable a deadly toy bent on destruction.
Be proactive and start your laundry.
Recreate a crime scene to get security off your scent.
Achieve a perfect game of skeeball.
Survive a power outage with gnome complications.
Charge your cell phone.
Correctly answer a riddle as if your life depended on it.
Take a photograph using the Haunted Camera.
Place the Magician's Top Hat on its rightful owner.
Survive the game to completion.
Discover Slappy's secret shame.
Find entry into the bookstore.
Find a way to call RL Stine without touching gross coins or a dirty phone receiver.
Find a way inside the Mall.
Convince your brother to give you a ride across town.
Narrowly escape defeat by wearing a talisman into the woods.
Look into an antique mirror and do some self reflection.
Solve a compression problem to reach the attic.
Access the mysterious dimension from every possible angle.
Use modern technology to give the second Ghost Child his heart's desire.
See to the needs of the 3 unexpected guests.
Face what lies beneath the sink... and survive!
Evict an elderly intruder.
Tell Aunt Dahlia about your weekend plans.
Toss 10 expendable items into a deep, dark hole.
Complete Area 1 and return home.
Intimidate a very deadly creature.
Find a way past the strange man in the woods.
Collect the cell phone from your school locker.